MUSOI. 



355 



the old arcliegoniiim {h, Fig. 243, B and C), the lower end 

 penetrates into the tissues of the leafy axis ; the upper end 

 develops into a spore-case, while the remainder becomes a 

 filiform stalk (seta) of greater 

 or less length. In the Spliag- 

 nacem, however, the sporogo- 

 nium does not greatly elongate, 

 but, on the contrarj% remains 

 quite short, while the end of 

 the leafy axis, soon after the fer- 

 tilization of the archegonium, 

 elongates into a slender leafless 

 stalk {pseudopodmm), which 

 carries up the developing sporo- 

 gonium upon its upper expand- 

 ed end {v, ps, Fig. 244, £ and 

 C). Essentially ' the same 

 structure is found in Andrm- 

 acecB and Pliascacem. 



464. — The ripe sporogo- 

 nium (capsule, theca, or spore- 

 case) is of various shapes, but 

 generally more or less cylindri- 

 cal or globose ; it differs much 

 in its particular structure in 



the different orders, but in all Fig. 244 —Development of the pporo- 



goniiim of Sphitonum ttcidifohum. A, 



certain internal cells become longitudinal section of a f^iiali,- flower ; 



,, ,, 1 • 1 T (^-r, ai'chegonia ; cA. young perichaitial 



spore mother-cells, Wnicn dl- leaves ; y, upper leaves of the shoot 



■ T - . j> ^ 11 m forming the perianth : B, longitudinal 



Vide into tour daughter-cells, section of a young >.porigoninm, sg ; 



iho sTinrP« Thp nan'snlp when *?'■ ''"?' ?' sporogonium, enclosed in 

 tne spores. i.lie capsuie, wneil thevaglnula, «;,■ 0, calyptra; ani-emains 

 rinp nnpn« hvfhp fallino- ofF nf "* old archegonium ; ps, the pseudopo- 



ripe, opens oy me idiung on oi ^^^^ ^^ ^,,^^^^ ^,,^.^5^ supports the 



a terminal lid (operculum) sporogonium. in the centre of the spo- 



*• -^ ' rogonium is the columella and the 



(SphaanaceCB and Bryacem), or curved row of spore mother-cells. c, 



: ■'- p , Tj • &phag7ium squarrosiifn, s^, ripe sporo- 



m a few cases by splitting yer- gonlum ; a, operculum ; c, to™ calyp- 



, . ,, / J 7 ^ -J.! tra ; gra, the elongated pseudopodium ; 



tically {AndrCBacem) ; 111 the eS,, perlchsetial leaves. All magnified.— 



small order Phascacem the cap- "' " imper. 

 sule is indehiscent, and the spores are set free only by its 

 decay or irregular rupture. The ripe spores are roundish 

 or more or less angled, and have a roughened or granulated 



